Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G61/00—Macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain of the macromolecule
  • C08G61/02—Macromolecular compounds containing only carbon atoms in the main chain of the macromolecule, e.g. polyxylylenes
  • C08G61/04—Macromolecular compounds containing only carbon atoms in the main chain of the macromolecule, e.g. polyxylylenes only aliphatic carbon atoms
  • C08G61/06—Macromolecular compounds containing only carbon atoms in the main chain of the macromolecule, e.g. polyxylylenes only aliphatic carbon atoms prepared by ring-opening of carbocyclic compounds
  • C08G61/08—Macromolecular compounds containing only carbon atoms in the main chain of the macromolecule, e.g. polyxylylenes only aliphatic carbon atoms prepared by ring-opening of carbocyclic compounds of carbocyclic compounds containing one or more carbon-to-carbon double bonds in the ring
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C33/00—Moulds or cores; Details thereof or accessories therefor
  • B29C33/56—Coatings, e.g. enameled or galvanised; Releasing, lubricating or separating agents
  • B29C33/60—Releasing, lubricating or separating agents
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C33/00—Moulds or cores; Details thereof or accessories therefor
  • B29C33/56—Coatings, e.g. enameled or galvanised; Releasing, lubricating or separating agents
  • B29C33/60—Releasing, lubricating or separating agents
  • B29C33/62—Releasing, lubricating or separating agents based on polymers or oligomers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C67/00—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
  • B29C67/24—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00 characterised by the choice of material
  • B29C67/246—Moulding high reactive monomers or prepolymers, e.g. by reaction injection moulding [RIM], liquid injection moulding [LIM]
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material

Definitions

• a method for the manufacture of molded products by the reaction injection molding (RIM) method using norbornene monomers, such as dicyclopentadiene (DCPD) and methyl tetracyclododecene, as molding materials has drawn attention in recent years to a wide range of fields such as automotive, electrical, electronic, civil engineering, house furnishings and leisure products. These molded products are often coated or painted in order to improve their appearance. Furthermore, it has been required to obtain many moldings in an as short a period of time as possible, from the viewpoint of productivity during manufacturing.
• RIM reaction injection molding
• mold-release agents for molds include silicone, mineral oils, wax, fatty acid derivatives, glycol, and other natural or synthetic compounds as such or diluted with solvents, talc, silica, alumina, mica, or other inorganic substances dispersed in solvents, or used in combination with wax in a paste form. In general, these mold-release agents are coated prior to the introduction of the molding materials into the molds.
• mold-release agents In the urethane RIM method, natural or synthetic waxes are commonly used as mold-release agents because of their low cost.
• mold-release agents include esters of fatty acids and monovalent or polyvalent alcohols, wood wax and other plant waxes, beeswax, lanolin and other animal waxes, paraffin, microcrystalline and other petroleum waxes, montan wax and other coal waxes, polyolefins, hydrocarbon oligomers and other synthetic waxes.
• Silicone is the most commonly used mold-release agent because of its good mold-release characteristics.
• the norbornene monomers are used as molding materials, the surface will become white when the molded products with good mold-release characteristics are released from the molds. This is known as the whitening phenomenon. Therefore, there is a problem of decreasing the commodity value of the molded products.
• silicone oils move readily or permeate into the molded products. Coating or adhesion processing of surfaces of such molded products is difficult. Since the molded products obtained by the RIM method often require coating, an improvement in their coatability is a technologically important topic.
• an inorganic substance such as talc or silica
• wax, glycol, or the like as a mold-release agent
• the present invention relates to a method for the reaction injection molding (RIM) of a norbornene monomer. More specifically, it relates to a reaction injection molding method capable of producing a molded product with good molding operation and excellent surface characteristics by using a mold coated with an organic fluorine compound having good mold-releasing characteristics.
• RIM reaction injection molding
• the objective of the present invention is to provide a molding method for obtaining molded products having good operability, increased molding cycles, excellent surface luster and smoothness, and no adverse effects on secondary processing such as coating and adhesion.
• a mold-release agent which contains an organic fluorine compound as an effective component.
• Such a mold-release agent is coated on the forming mold in the reaction injection molding method wherein a molding material containing at least one norbornene monomer as the major component is poured into the mold.
• the present inventors have found that molded products with good molding characteristics and excellent surface characteristics can be obtained.
• the gist of the present invention is a reaction injection molding method characterized by the fact that a mold coated with an organic fluorine compound mold-release agent is used in carrying out the method wherein a norbornene monomer and a metathesis catalyst are introduced into the mold.
• organic fluorine compound mold-release agents which can be used in the present invention are those which are liquids or solids at the molding temperature.
• fluorine-containing organic compounds suitable herein include fluorinated ethers, addition polymers of fluorinated olefins, fluorinated organic acid compounds, salts of perfluorosulfonic acids, and the like.
• fluorinated ethers include methyl polyoxyethylene perfluorononyl ether, methyl polyoxypropylene perfluorononyl ether, methyl polyoxyethylene perfluorooctyl ether, methyl polyoxyethylene perfluorostearyl ether, ethyl polyoxyethylene perfluorononyl ether, and other perfluoroalkyl ethers; and ring-scission polymers of 3-perfluouropentyl-1,2-epoxy propane, ring-scission copolymers of 3-perfluoropentyl-1,2-epoxy propane and ethylene oxide, epichlorohydrin, or the like, and other ring-scission polymers of fluoro epoxide with resinous or oily structures.
• addition polymers of fluorinated olefins include polyhexafluoropropane, polytetrafluoroethylene, polytrifluorochloroethylene, polyfluorovinylidene, and others are available. These may be oily or resin-forming polymers.
• fluorinated organic acid compounds include sodium salts, potassium salts, and the like of perfluoroacetic acid, perfluoroethylacetic acid, and other salts of perfluorocarboxylic acids; methyl esters, ethyl esters, propyl esters, butyl esters, and other alkyl esters of perfluorocarboxylic acids; polymers of perfluoroalkyl acrylate or methacrylate, and copolymers of these monomers with butyl acrylate, butyl methacrylate, stearyl acrylate, stearyl methacrylate; salt of perfluorosulfonic acid and the like.
• organic fluorine compound mold-release agents may be used alone or in combinations of two or more of them.
• mold-release agents other than the organic fluorine compound mold-release agents may also be used in combination in order to increase the mold-release characteristics as long as the polymerization of the norbornene monomers is not hindered. Amounts of addition have no special restrictions. However, from the viewpoint that the performance of the organic fluorine compound mold-release agents is not reduced, less than 50 weight percent, especially less than 30 weight percent are suitable with respect to the other mold-release agents, based on the weight of the active ingredients of the mold-release agent.
• organic fluorine compound mold-release agents which can be used in the present invention are generally utilized in solution or dispersion in organic solvents or aqueous media.
• organic solvents include methanol, ethanol, propanol, isopropanol, and other alcohols; acetone, methyl ethyl ketone, methyl isobutyl ketone, and other ketones; ethyl ether, isopropyl ether, dioxane, tetrahydrofuran, and other ethers; ethyl acetate, butyl acetate, and other esters; hexane, cyclohexane, toluene, xylene, and other hydrocarbons; carbon tetrachloride, methylene chloride, trichloroethylene, perchloroethylene, trichloroethane, trichlorofluoromethane, tetrachlorodifluoroethane, trichlorotrifluoroethane, and other halogenated hydrocarbons. These may be used alone or in combination with each other or with water.
• a cationic, anionic, or nonionic surfactant In the dispersion of fluorine compound mold-release agents in aqueous media, it is acceptable to carry out emulsification by using a small amount of a cationic, anionic, or nonionic surfactant. If the surfactants are used in large quantities, problems like reduction in the mold-release characteristics, poor curing of molding materials, and color change, may occur. Therefore, it is preferable that the surfactant be used in a small quantity.
• the amount of surfactants used is ordinarily less than 1.0 part by weight, preferably 0.05 to 1.0, and more preferably less than 0.5 part by weight, based on 100 parts by weight of water.
• the concentrations of the organic fluorine compound mold-release agents in the organic solvent solutions or aqueous dispersion solutions are preferably in the range of 0.05 to 10 weight percent in general.
• concentrations of the mold-release agents can be adjusted properly according to the objectives of usage. For example, for a one time use of the mold, less than 0.1 weight percent will be sufficient. On the other hand, if molding is to be carried out several times by coating a molding-release solution or dispersion once, it will be proper to have 0.5-5 weight percent or higher.
• the temperature of the molds there are no special restrictions on the temperature of the molds during the application of the mold-release agents.
• the molds are at room temperature of 25° C. to 120° C., preferably 30°-90° C. It is convenient to the operation to maintain the temperature of the mold at the molding temperature.
• the materials of the molds which can be used in the RIM method of the present invention are not restricted to metals.
• any of the resins, wood, cement, and the like can also be used. From the viewpoint of economy, resin molds, electroformed molds or the like are popular.
• the shapes of the mold may range from a simplistic structure to a complicated one. For example, if a mold-release agent of the present invention is coated on ribs, bosses or other portions from which mold releasing is normally difficult, de-molding can be carried out readily with ease.
• the monomers which can be used as the molding materials in the present invention are those which have at least one norbornene ring. However, in order to obtain polymers with high thermal deformation temperatures, it is preferable to use polycyclic norbornene monomers having more than three rings.
• the polymers formed are of the thermosetting type. Therefore, it is preferable to use crosslinking monomers.
• norbornene monomers include 2-norbornene, 5-methyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-hexyl-2-norbornene, 5-ethylidene-2-norbornene, 5-phenylnorbornene and other bicyclic compounds; dicyclopentadiene, dihydrodicyclopentadiene and other tricyclic compounds; tetracyclododecene, methyl tetracyclododecene, ethyl tetracyclododecene, dimethyl tetracyclododecene, ethylidene tetracyclododecene, phenyl tetracyclododecene and other tetracyclic compounds; tricyclopentadiene and other pentacyclic compounds; hexacyclic norbornene compounds
• tricyclic compounds, tetracyclic compounds and pentacyclic compounds are preferred from the viewpoint of easy availability, reactivity, heat resistance, etc.
• the crosslinking monomers are polycyclic norbornene monomers having two or more reactive double bonds. Specific examples thereof include dicyclopentadiene, tetracyclopentadiene, trimers and tetramers of cyclopentadiene, and the like. Therefore, if the norbornene monomer and the crosslinking monomer are the same substance, it will be unnecessary to use another monomer if a crosslinked polymer is desired.
• norbornene monomers may be used alone or in a mixture thereof.
• the norbornene monomers having more than three rings can also be obtained by the heat treatment of a dicyclopentadiene.
• a dicyclopentadiene may be heated in an inert gas atmosphere at a temperature of 120°-250° C. for 0.5-20 hours.
• a monomer mixture containing tricyclopentadiene and the unreacted dicyclopentadiene can be obtained.
• Cyclobutene, cyclopentene, cyclopentadiene, cyclooctene, cyclododecene and other monocyclic cycloolefilns which can be polymerized by ring opening polymerization can be used in combination with one or more previously mentioned norbornene monomers in a range which does not destroy the objectives of the present invention, preferably up to 20%, more preferably 1-10% by weight, based on the weight of the entire monomer charge.
• the metathesis catalyst system described herein includes a catalyst and an activator or a cocatalyst.
• the catalysts which can be used in the present invention may be any of the methathesis catalysts known as the catalysts for the ring opening polymerization of norbornene monomers.
• Such catalysts see Japanese Kokai Patents Nos. Sho 58-127728, Sho 58-129013, Sho 59-51911, Sho 60-79035, Sho 60-186511, and Sho 61-126115.
• Such catalysts include organoammonium molybdates and tungstates which are insensitive to oxygen and moisture.
• metathesis catalysts include halides, oxyhalides, oxides, organic ammonium salts, or the like of tungsten, molybdenum, and tantalum.
• activators or cocatalysts include alkyl aluminum halides, alkoxy alkyl aluminum halides, aryloxy alkyl aluminum halides, and organic tin compounds.
• chloroform carbon tetrachloride, hexachlorocyclopentadiene, and other halogenated hydrocarbons, as illustrated in Japanese Kokai Patent No. Sho 60-79035, as well as silicon tetrachloride, germanium tetrachloride, lead tetrachloride, and other metal halides.
• the metathesis catalysts are generally used in the range of 0.01-50 mmol, preferably 0.1-10 mmol, per mol of the monomers.
• the metathesis activators or cocatalysts are generally used in the molar range of 0.1-200 moles, preferably 2-10 moles per mole of the catalyst compound.
• any of the metathesis catalysts and the activators in a monomer solution, they can also be used in suspension or in solution in a small amount of a solvent as long as the properties of the products are essentially not damaged.
• the present invention it is possible to use a method in which the norbornene monomers are subjected to ring-opening polymerization in a bulk form by a metathesis catalyst. It is acceptable to use a small amount of a solvent as long as it is essentially bulk polymerization.
• the norbornene monomers are divided into two liquids and placed in separate containers. A metathesis catalyst is added to one of them, and an activator is added to the other. In this fashion, two stable reaction solutions are prepared and stored. These two solutions are mixed and then poured into a mold of a desired shape. Here, ring-opening polymerization in bulk is carried out.
• impingement mixing apparatus known conventionally as the RIM molding apparatus can be used to mix the two reaction solutions.
• the containers containing the two reaction solutions will be the supply sources of the separate streams.
• the two streams are mixed instantaneously in the mixing head of the RIM machine and then the mixed streams are poured into a heated mold where bulk polymerization is allowed to proceed immediately to yield a thermoset, molded product.
• impingement mixing apparatus can be used in this manner, the present invention will not be restricted to such a mixing means.
• the pot life at room temperature is longer than one hour, it may be injected or poured in several intervals or increments into a preheated mold, as described in Japanese Kokai Patent No. Sho 59-51911 and U.S. Pat. No. 4,426,502.
• the mixed streams may also be poured continuously into the mold.
• the apparatus can be miniaturized in comparison with the impingement mixing apparatus. Furthermore, it has an advantage of operating at a low pressure. If the amount of glass fibers or other fillers is large, the reaction solutions can be injected uniformly into the mold by reducing the pouring speed.
• the present invention is not restricted to a method using two reaction solutions. As is readily understood by people in the industry, a variety of modifications is possible. For example, a third stream obtained by placing a monomer and a desired additive into a third container may be used.
• the mold temperature is generally more than 30° C., preferably 40°-200° C., even more preferably 50°-120° C.
• the mold pressure is generally in the range from 0.1 to 100 kg/cm 2 .
• the polymerization time can be selected properly. Ordinarily, it is shorter than about 20 minutes, preferably less than 5 minutes. However, it may also be longer than this.
• reaction solutions are generally stored or used under nitrogen gas or other inert gas atmosphere. However, it is also acceptable that the mold is not necessarily sealed with an inert gas.
• the characteristics of the polymers obtained can be improved.
• antioxidants there are antioxidants of the phenol type, phosphorus type, amine type, or the like for polymers described herein.
• fillers there are milled glass, glass long fibers, glass mat, carbon black, talc, calcium carbonate, mica, and other inorganic fillers.
• elastomers there are natural rubber, polybutadiene, polyisoprene, styrene-butadiene copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, ethylene-propylene-diene terpolymer, ethylene-vinyl acetate copolymer, and hydrogenated products thereof.
• the additives may be premixed with any or both of the reaction solutions. Alternatively, they may be placed in the cavity of a mold beforehand.
• DCPD Dicyclopentadiene
• Solution A and Solution B kept in separate containers at 35° C. were delivered with constant flow pumps into the mixing head so that the two solutions had a volumetric ratio of 1:1. After mixing, the mixture of the two solutions was poured into a desired mold.
• the mold was made of aluminum and had a flat plate-shaped cavity of 500 mm ⁇ 500 mm ⁇ 3 mm. Before the molding feedstock was poured, the mold surface was sprayed with the various fluorine compound mold-release agents shown in Table I while the mold was open. The solvent was evaporated. For comparison, a case in which a commonly used mold-release agent was employed is also shown.
• the mold temperature was 70° C.
• the mold was closed and the molding material was poured into it. After the curing reaction was carried out for 90 seconds, the mold was opened.
• Example 1 A mold coated with the organic fluorine compound mold-release agent shown in Example 1 was used. After the first molding, the same reaction solutions as in Example 1 were used. Under the same conditions, molding was repeated 10 times without recoating with the mold-release agent. For all ten times, the mold-release characteristics of the molded products from the mold were good. Whitening of the molded product surface did not occur. The coating characteristics were 100/100 and good.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)
• Injection Moulding Of Plastics Or The Like (AREA)
• Casting Or Compression Moulding Of Plastics Or The Like (AREA)

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• 1988
  • 1988-07-19 JP JP63178260A patent/JPH0229308A/ja active Pending
• 1989
  • 1989-07-17 US US07/380,424 patent/US5008065A/en not_active Expired - Fee Related
  • 1989-07-18 EP EP19890113142 patent/EP0351770A3/de not_active Withdrawn
  • 1989-07-18 CA CA000606023A patent/CA1323158C/en not_active Expired - Fee Related
  • 1989-07-19 DK DK358189A patent/DK358189A/da not_active Application Discontinuation
  • 1989-07-19 BR BR898903580A patent/BR8903580A/pt unknown

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